21 Engine difficult to start, turbocharger damaged, V8 4.0TFSI
21 18 28 2044640/3 May 14, 2018. Supersedes Technical Service Bulletin Group 21 number 17-27 dated
November 21, 2017 for reasons listed below.
Model(s)

Year

VIN Range

Vehicle-Specific Equipment

A8, S7, S8,
S8+, RS7,
and RS7+

2016

All

4.0L

A8

2017

000001 - 019190

4.0L

S8

2017

000001 - 901368

4.0L

S7

2017

000001 - 115286

4.0L

RS7, RS7+

2017

000001 - 904264

4.0L

Condition
REVISION HISTORY
Revision

Date

Purpose

3

-

Revised header data (Added VIN breaks for 2017 models)
Revised Production Solution (Added information)
Revised Service (Added Note and updated Step 7)
Revised Required Parts and Tools (Added part numbers)

2

11/21/2017

Revised Required Parts and Tools (Updated quantity and part numbers)

1

02/02/2017

Initial publication

Customer statement:
 Engine cannot be started or only with difficulty.
 Engine makes unusual noises when accelerating.
 Engine has reduced performance.
Workshop findings:
 Damage on turbocharger impeller fins, increased free play on impeller shaft of turbocharger or broken impeller
shaft.

Page 1 of 7
© 2018 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of
America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.

Technical Background
Damage to the turbocharger is rarely directly the result of turbocharger failure. Therefore, it is important to
perform further checks to find the root cause, to avoid repeat repairs.
Known causes for turbocharger damage:
 Performance increases by tuned ECM
 Non-compliance with service intervals
 Incorrectly fitted oil filter element
 Leaks in intake tract allowing outside unfiltered air and debris into the turbocharger
 Poor oil supply of turbocharger

Production Solution
Optimized oil strainer 079115175G for oil supply lines to turbochargers in the cover in the inner valley of
engine. The oil strainer and check valve 079103175C must always be replaced to ensure proper oil flow to
the turbochargers.

Service
1. Perform the Guided Functions with the diagnosis tester: "01 check warranty information." Then check for an
entry with the vehicle data in ELSA under warranty code.
 All information must be documented on attached Checklist and stored with the Repair Order.
2. Check the hardware version of the
engine control unit. An X version
indicates that the engine control unit
was replaced/or is modified (Figure
1).

Figure 1. Correct hardware version number.
3. Check the intake tract for leaks. Review the repair history for possible previous repairs on the intake tract.
4. Measure the oil pressure at idle and 2000 rpm according to ElsaPro.

Page 2 of 7
© 2018 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of
America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.

5. Visually assess the condition of the damaged turbocharger from both sides. No oil marks (charge air and
exhaust side) could be another indication for a poor oil supply to the turbocharger.

6. Check the oil filter for correct installation and correct filter part number 079115561J. If the oil filter is not
centrally fitted, the engine oil may not be filtered, entering the oil supply of the turbocharger due to the
crooked position of the oil filter element.
 Check the installation of the oil filter bypass valve according to service measure 17F2.
 Check the oil supply line for through flow and oil deposits.
 Check the oil drain hoses for through flow and oil deposits.
Note:
This TSB is not replacing any Repair Manual instructions, this TSB is meant to supplement the Repair Manual.
See ElsaPro, Engine >> 8-Cylinder Direct Injection 4.0L 4V TFSI Engine >> 21 Turbocharger >> Turbocharger,
Removing and Installing.
7. Replace both of the turbochargers as well as the oil strainer and check valve in the inner valley of engine
according to ElsaPro and observe all instructions.
8. Change the engine oil including oil filter.
9. Follow the installation instructions in ElsaPro for the turbochargers exactly including:
 Filling the turbocharger at the supply line connections with engine oil.
 To ensure the turbocharger is supplied with enough oil, let the engine run at idle for approximately one
minute after starting, do not increase rpm.
Note:
Failure to follow the TSB and ElsaPro instructions may lead to premature turbocharger failure which may
be reviewed by Warranty.

Warranty
Claim Type:

 110 up to 48 Months/50,000 Miles.
 G10 for CPO Covered Vehicles – Verify Owner.
 If vehicle is outside any warranty, this Technical Service Bulletin is
informational only.

Service Number:

2130

Page 3 of 7
© 2018 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of
America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.

Damage Code:

0010

Labor Operations:

For all models:
Turbocharger replace

2130 5671

50 TU

Oil pressure check

1703 0199

80 TU

Check intake and exhaust system for debris,
additional time is included in Turbocharger
remove + reinstall

2130 0199

20 TU

Remove + reinstall oil strain and check valve

1726 2099

70 TU

Check that oil bypass valve is fitted correctly

1701 0199

10 TU

Engine oil and filter change

1701 1799

40 TU

For A8 and S8:
Air intake distributor remove + reinstall without 2446 1921
night camera and radar sensor

470 TU

Turbochargers remove + reinstall

2130 2071

520 TU

Turbochargers remove + reinstall

2130 2071

470 TU

(S6/S7 only) Air intake distributor remove +
reinstall without night camera and radar
sensor

2446 1921

600 TU

(RS7 only) Air intake distributor remove +
reinstall without night camera and radar
sensor

2446 1923

690 TU

GFF

0150 0000

30 TU

Road test prior to service procedure

0121 0002

10 TU

Road test after service procedure

0121 0004

10 TU

For S6, S7, and RS7:

Diagnostic Time:

Claim Comment:

As per TSB # 2044640/3

All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures
Manual. Claims are subject to review or audit by Audi Warranty.

Required Parts and Tools
Page 4 of 7
© 2018 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of
America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.

Always check with your Parts Department and/or ETKA for the latest information and parts bulletins. Please
check the Repair Manual for fasteners, bolts, nuts, and screws that require replacement during the repair.
Part Number

Part Description

Quantity

079103175C

Check valve

1

079115175G

Oil strainer

1

Order by VIN

Left waste gate vacuum unit with actuator rod

1

Order by VIN

Right waste gate vacuum unit with actuator rod

1

079103161Q

Cover Gasket

1

N 90303801

Lower oil supply o-rings 9x1.5 black

2

N 91056801

Upper oil supply o-rings 12x2 black

2

WHT006901A

Oil return o-rings 14.5x2

2

N 90465003

Water tube o-rings 23x2.6

3

N 90409501

Clamp breather hoses

4

079129717K

Intercooler housing gasket right side

1

079129717J

Intercooler housing gasket left side

1

079145818

Throttle body gasket

1

079103583

Breather seals

3

N 90686902

Spring clips 23x12 breather hoses

4

WHT006335A

Turbo coolant pipe o-rings lines (blue 2.0mm)

4

Note:
Installed seals are based on which pipes are installed
(see TSB 2036167).
WHT006537

Turbo coolant pipe o-rings lines (black 2.8mm)

4

Note:
Installed seals are based on which pipes are installed
(see TSB 2036167).
WHT001011A

Coolant supply pipe lower o-rings yellow 12.2x1.65

2

Page 5 of 7
© 2018 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of
America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.

Order by VIN

Left turbocharger

1

Order by VIN

Right turbocharger

1

WHT005529

Inlet pipe o-rings

2

079253039M

Exhaust manifold gaskets

2

N 90894601

Manifold nuts M8

16

G 052112A3

Hot bolt paste 170G

1

4G0253115D

Turbocharger outlet gaskets

2

N 91153902

Turbocharger studs

10

N 91130802

Manifold nuts

10

N 0138495

Drain plug gasket

1

079198405D

Oil filter kit

1

G 013A8J1G

Coolant additive

1

Outside material

Distilled water (obtained locally)

Shop supply

Tool Number

Tool Description

3371

Gauge – Gap adjustment tool

V.A.G 1342

Oil pressure gauge kit

V.A.G 1274/8

Adapter

V.A.G 1274/10

Adapter

VAS 6096

Cooling system charge unit

T10007 A

Refractometer
Approved battery charger

Additional Information
Page 6 of 7
© 2018 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of
America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.

More information can be found at the following resources:
 ElsaPro, Engine >> 8-Cylinder Direct Injection 4.0L 4V TFSI Engine >> 21 Turbocharger >> Turbocharger,
Removing and Installing.
The following Technical Service Bulletin(s) will be necessary to complete this procedure:
 TSB 2028842, 01 Automatic detection of unauthorized chip tuning (TD1 warranty key).
 TSB 2036167, 19 Coolant pipe seepage on turbocharger.
All parts and service references provided in this TSB (2044640) are subject to change and/or removal.
©2018 Audi of America, Inc. All rights reserved. Information contained in this document is based on the latest
information available at the time of printing and is subject to the copyright and other intellectual property rights of
Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any
time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted in
any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these
materials be modified or reposted to other sites without the prior expressed written permission of the publisher.

Page 7 of 7
© 2018 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Audi of
America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without the prior expressed written permission of the
publisher.